This template takes another template-name and some associated pipe-tricked(numbered) parameters (or 'pass parameters'), and displays them as an 'example demonstration' of how the template-name template could be coded, literally. Its primary use is in instruction and documentation.

Specifics: Up to five pass parameters (numbered or nowiki-keywords) for the specified template are displayed as 'placeholders', and over 5 parameters can be displayed using a coded vertical-bar (as in "&#124;..."). A keyword parameter can be used, when tagged as a nowiki-keyword: "<nowiki>siz=10<\nowiki>" with each keyword parameter surrounded by "<nowiki>" tags; see Examples at bottom. For more details, see the this talk page.

Exceptions: If the intended template lists numerous/keyword parameters, then perhaps this template should really not be used, and just hardcode the usage in double-braces, putting only nowiki-braces "{{" to start, such as: "<nowiki>{{<\nowiki>Anytemplate |arg1=23 |siz=250px}}".

If given no additional parameters except 'template name' ({{{1}}}), it presents the same as the similar {{Tl}} macro template -- a blue link nested in curly-braces-- the same as a user would apply the template without parameters, but with a noticably clearer font and spacing on most modern browsers.

Comparatively, {{Tl}} will not take or display additional parameters, and for minor technical reasons, may preferred for mere listing and referencing in long pages involving a lot of template expansions1.

Additionally, Tlx will take a 'named' parameter 'SISTER' to link interwiki to other sister projects such as one of these examples: '|SISTER=W:', 'Tlx|SISTER=M:', 'Tlx|SISTER=Q:', 'Tlx|SISTER=S:', allowing documentation or discourse about a template across interwiki boundaries. Small 'front end' Shell or convience templates {{Tlxw}} and {{Tlxm}} are typing-aid templates available at Meta for automatic substitution in discussions about templates on Wikipedia or Meta.

This usage also applies to interwiki capable template variations

{{Tlxc}} -- which links to templates on Wikimedia Commons (The Commons).

{{Tlx}}
is a generalization of {{Tl|x}}, {{Tlp|x|y}},
etcetera with arguably better readable
output. This depends on the browser, but too narrow
uses of "{", "|", "}" in conjunction
with links can be hard to read.